Friday, March 25, 2016

The longest game of the week from TWIC 1114 was a 158 move marathon from the HD open in Vietnam. The game reached an ending which is most player's nightmare, a queen and pawn endgame. The ideas in these endgames are usually fairly simple, but implementing those ideas is usually tough because of the amount of queen moves that have to be taken into account.

This was the position after 101 moves. Here are a few general observations first.

- I like IM Robert Jamieson's summing up of queen endings: put your queen on a central square and see what happens. White's queen takes up a dominant spot in this endgame.

- white is trying to win this, and even though the position may be theoretically level (though it may not!), white runs no risk of continuing in this position, and hoping that black makes an error.

- black needs to avoid an exchange of queens unless black's king can get to e6 with the opposition.

This is a draw with white to move, but white can still try here, hoping that black is not aware of how to draw. 1.Kf3 Kf5? [1..Ke7 would draw. Black just needs to be ready to move to e6 if white ever plays Ke4] 2.Ke3 Ke6 3.Ke4 and we reach the position above is reached with black to move. That is a win for white as after 3..Kd6 4.f5 gxf5 5.Kxf5 Ke7 6.g6

Now white wins after 6..Ke8!? [Hoping for 7.Kf6? Kf8=] 7.Ke6! Kf8 8.Kf6 Kg8 9.g7 and the pawn will promote.

- the defending side needs to be aware of all possible drawing possibilities, including repetition of positions and the 50 move rule. A few weeks ago I showed a blitz game where the 50 move rule was exceeded but the draw wasn't claimed. This is understandable in a blitz game where a record isn't being kept. In a standard rated game it is unforgivable. Here's the position from the longest game of the week after 151 moves.

Clearly, there have been no captures since the original position, nor have there been any pawn moves. In this position, black should have claimed a draw according to the 50 move rule. Instead the game continued, and black resigned 7 moves later!

- endgames are often decided by fatigue rather than ability. Black was clearly tired in this game, missing the 50 move draw, and then blundering soon after.

From the above position, white would ideally like to force an exchange of queens, so all the time the white queen is looking to block checks from black's queen and at the same time pinning black's queen to the black king. The game continued 152.Qe5 Qd3+ 153.Ke7 Qa3+ 154.Qd6 Qa7+

Black's queen has plenty of space to keep checking white's king and white cannot avoid the checks but white skilfully heads towards f6 with the king. White's queen has a dominating position covering a number of squares, and threatening black's king. Black continued to hassle the white king. 155.Qd7 Qc5+ 156.Kf6

This is a critical position. White has made great progress, threatening mate on g7, and the pawn on g6. A black check on the 6th rank will be blocked by white's Qe6+ forcing an exchange of queens, so black has nothing left. The game finished 156..Qc3+ 157.Kxg6 [No more 50 move draw claim] 157..Qc2+ 158.f5 and black resigned ahead of the imminent mate.